基于电解海水的模拟船舶柴油机废气脱硝

Simulated gas denitrification of marine diesel engine by seawater electrolysis

实验研究了电极间距、电解时间和电流密度等不同电解条件对电解液余氯浓度和pH值的影响,进而以电解液中的余氯为氧化剂,结合模拟烟气和自行设计制作的小型湿法喷淋反应器,进一步研究了电解液余氯浓度和pH值对烟气脱硝效果的影响,并分析探讨了相关脱硝反应机理。结果表明,在电解时间一定时,电极间距由5 mm增加至25 mm过程中,电解液中余氯浓度变化不明显。随着电解时间和电流密度的增加,余氯浓度基本呈线性增加。随电解时间的增加,电解液的pH值先下降后增加,且电流密度越大,pH值变化越不明显。NO和NO_x的脱除率均随余氯浓度的增加而显著提高,但逐渐趋于稳定。在电解时间为5 min、电流密度为100 m A·cm-2时,NO和NO_x的脱除率分别达到69.7%和53.7%。在电解液pH值由5.5增加至9的过程中,NO和NO_x的脱除率均先增加后降低,在pH值等于7时,NO和NO_x的脱除率最大,分别为81%和58%。

Experiments were conducted to investigate the effects of various electrolytic conditions （electrode space, electrolysis time, and current density） on the active chlorine concentrations and the pH values of an electrolytic solution.As a strong oxidant, active chlorine in electrolyzed seawater was used to remove NO from simulated flue gas.The effects of the active chlorine concentration and pH value on NO removal were studied in a scrubbing reactor.The experimental results indicate that the active chlorine concentration changes little with increasing the electrode space from 5 to 25 mm.However, the active chlorine concentration increases linearly with increases in electrolysis time and current density.With an increase of electrolysis time, the pH value decreases slightly at the beginning and then increases.The larger the current density became, the smaller the changes in pH became.With an increase in active chlorine concentration, the removal efficiencies of both NO and NOx clearly increased.When the current density was 100 mA·cm-2 for an electrolysis time of 5 min, the removal efficiencies of NO and NOx were 69.7% and 53.7%, respectively.When the pH value of the electrolyzed seawater increased from 5.5 to 9, the removal efficiencies of NO and NOx increased slowly, but decreased upon further increasing the pH value.When the pH value was 7, the removal efficiencies of NO and NOx were 81% and 58%, respectively.